LAUSR

Abstract Presence of nutrients in municipal sewage water in high concentrations has raised awareness of their reuse as a vital limiting resource. With an aim to recover the nutrients in a form that can be used as a soil amendment, a novel biocompatible nanocomposite (BC-P@MNP) was fabricated using green methods. Polysaccharide induced biogenic magnetite nanoparticles (P@MNP) were immobilized onto the biochar of jackfruit peel (BC) to fabricate BC-P@MNP. Microwave irradiation employed during the fabrication of BC-P@MNP involved less energy consumption, high yields and better adsorption performance as compared to BC and other reported biochar-composites. Structural features like mesoporosity, crystallinity, magnetism, functionality and nano-sized dimension was demonstrated in BC-P@MNP. Under optimized conditions, batch studies revealed a maximum adsorption efficiency of 7.94 mg/g and 5.26 mg/g for phosphates and nitrates respectively. Thermodynamics revealed the feasibility and exothermicity of the system. The high selectivity in the presence of competing co-anions, high regeneration capacity and better separability enable BC-P@MNP to be used as advanced, economical adsorbent for wastewater applications. High nutrient recovery and biocompatibility ensured the potential of the spent adsorbent to be used as a soil amendment. Breakthrough curves obtained from fixed-bed column tests conducted on agricultural wastewater demonstrated the use of higher bed depths and lower flow rates for achieving higher phosphate removal as well as for ensuring lower unused column bed. The study demonstrated the technological advancement of a biogenic nanocomposite fabricated from green methods over other reported adsorbents for removal and recovery of nutrients from water.